Thank You Everyone for the replies. They will be most helpful when I design ours.

We have an older 15 kw Onan. I know it will not get used all the time but I also know we will use it on occasion. The first thing I will do is fire the ole gal up and let her run for a while and use my temp gun and measure the temp at the exhaust outlet. This will help me determine what kind of piping to use.

Y'all have given me much to consider and all good ideas.

I have a much better understanding on what I should look for and how to do it.

I threw a temporary one together out of stuff I had laying around my workshop and it worked so well I never changed it. I used an EMT seal tight connector on the exhaust pipe and a 90 degree 1 1/2" EMT pipe into it. I had a 5í and a 3í section of double wall 4" exhaust vent pipe (the type for gas hot water heater I believe) that can be assembled/disassembled by sliding the locking rings up and down. I just used a hose clamp to attach a hook to one of the pipes and added some padding to it to dampen any vibration that might get transmitted from the pipe. My stack simply hangs from the rain gutter loosely over the 90. I wrapped the tip of the 90 with exhaust wrap to dampen any vibration that might get transmitted to the stack. The entire thing goes up in less than 30 sec. It works beyond any of my initial expectations and because it is double walled, does not get hot.

Just another way,

Laryn

« Last Edit: June 11, 2008, 07:37:57 AM by Barn Owl »

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L. Christley - W3EYE Amateur ExtraBlue Ridge Mountains, S.W. VirginiaItís the education gained, and the ability to apply, and share, what we learn.Have fun, be great, that way you have Great Fun!

Difference is that I used 4" fiberglass pipe for the stack - 2 pieces that screw together. Everything else is common parts from the hardware giant, including the 2" long bend piece of galvanlize conduit for the bottom.

I couldn't begin to know where one could find it elsewhere but I lucked out. While I still lived in Anchorage I found a supplier that had some salvage pieces that had been rejected by a sewer contractor. I bought a 20' stick that had been damaged in the center part but had a good hub on one end and a good male thread on the other. $60 and they even cut it to give me the two end pieces at about 4-1/2 feet each.

I have some 3" shop exhaust hose that I used a plumbing reducer to fit over the exhaust pipe to vent the generator when I would ran it in a warehouse it was once stored in. I thought that I would just use the same hose by hoisting it up the side of the bus when I needed it. Is that too low class?